Measurement and Modeling of NO2 Traffic-Related Air Pollution in Doha, Qatar

Abstract

Six major intersections along C-ring road of Qatar were investigated for NO2 emission. NO2 is considered to be a marker of vehicular pollution thus in this study, its relationship was established with traffic volume in each intersection during December 2012 and March-April 2013. Significant differences were established between the NO2 concentration in each intersection. Higher concentrations were observed in areas with high traffic volume. The magnitude of the dispersion of the NO2 emission was further evaluated by monitoring two proximity points within 250m on each side of the main intersection. It was observed that there were no significant differences between the NO2 concentrations measured in the main intersection and the two proximity points. It was evident that the vehicular traffic continuously flow within the area. The effects of the dispersion of the automobile emissions on the other hand was investigated by considering neighboring points which were situated away from the main intersection. Significantly lower concentrations were recorded in the areas away from direct impact of the emissions from automobile exhaust. It was evident in the study that traffic related emissions from automobile exhaust. It was evident in the study that traffic related emissions significantly influenced the NO2 concentrations. However, meteorological conditions were also found to influence the level in addition to the topographical structure within the area. The CALINE 4 model employed during the study estimated the influence of the measured NO2 concentration on the predicted NO2 value by only 31.12%. The low percentage may have accounted for the uncertainties brought about the vehicle emission factor, non-availability of temporal dynamics during the time of sampling.